webpack/hot/dev-server.js

Packs CommonJs/AMD modules for the browser. Allows to split your codebase into multiple bundles, which can be loaded on demand. Support loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/
/* globals __webpack_hash__ */
if (module.hot) {
	var lastHash;
	var upToDate = function upToDate() {
		return lastHash.indexOf(__webpack_hash__) >= 0;
	};
	var log = require("./log");
	var check = function check() {
		module.hot
			.check(true)
			.then(function (updatedModules) {
				if (!updatedModules) {
					log("warning", "[HMR] Cannot find update. Need to do a full reload!");
					log(
						"warning",
						"[HMR] (Probably because of restarting the webpack-dev-server)"
					);
					window.location.reload();
					return;
				}

				if (!upToDate()) {
					check();
				}

				require("./log-apply-result")(updatedModules, updatedModules);

				if (upToDate()) {
					log("info", "[HMR] App is up to date.");
				}
			})
			.catch(function (err) {
				var status = module.hot.status();
				if (["abort", "fail"].indexOf(status) >= 0) {
					log(
						"warning",
						"[HMR] Cannot apply update. Need to do a full reload!"
					);
					log("warning", "[HMR] " + log.formatError(err));
					window.location.reload();
				} else {
					log("warning", "[HMR] Update failed: " + log.formatError(err));
				}
			});
	};
	var hotEmitter = require("./emitter");
	hotEmitter.on("webpackHotUpdate", function (currentHash) {
		lastHash = currentHash;
		if (!upToDate() && module.hot.status() === "idle") {
			log("info", "[HMR] Checking for updates on the server...");
			check();
		}
	});
	log("info", "[HMR] Waiting for update signal from WDS...");
} else {
	throw new Error("[HMR] Hot Module Replacement is disabled.");
}